System and method for adaptive access network query protocol (ANQP) element provisioning

ABSTRACT

A method embodiment includes receiving, by an access point (AP), a request for an access network query protocol (ANQP) element, and multicasting the ANQP element as an ANQP information element (IE), wherein the ANQP IE is configured in accordance with a format transmittable by the AP in a multicast.

This application is a continuation of U.S. patent application Ser. No.13/786,081, entitled “System and Method for Adaptive Access NetworkQuery Protocol (ANQP) Element Provisioning,” filed on Mar. 5, 2013,which application is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to a system and method forwireless communications, and, in particular embodiments, to a system andmethod for adaptive access network query protocol (ANQP) elementprovisioning.

BACKGROUND

Generally, known wireless standards, such as Institute of ElectricalEngineering (IEEE) 802.11 or Hotspot 2.0, provide mechanisms for accessnetworks (e.g., access points (APs)) to communicate information to astation (STA) prior to association. The mechanisms include a genericadvertisement service (GAS) protocol, beacons, and a proberequest/response framework. These mechanisms may be used to provide anunassociated STA with necessary information, so that the STA may selectan appropriate wireless network.

SUMMARY OF THE INVENTION

These and other problems are generally solved or circumvented, andtechnical advantages are generally achieved, by preferred embodiments ofthe present invention which includes adaptive network query protocol(ANQP) element provisioning in WiFi beacons.

In accordance with an embodiment, a method for adaptive network queryprotocol (ANQP) signaling includes receiving, by an access point (AP), arequest for an ANQP element, and multicasting the ANQP element as anANQP information element (IE), wherein the ANQP IE is configured inaccordance with a format transmittable by the AP in a multicast.

In accordance with another embodiment, an access point (AP) includes aprocessor, and a computer readable storage medium storing programmingfor execution by the processor, the programming including instructionsto receive a request for adaptive network query protocol (ANQP)information, format at least a portion of the ANQP information as one ormore ANQP information elements (IEs), wherein the ANQP IEs areconfigured in a format in accordance with a standard, and include theone or more ANQP IEs in a multicast.

In accordance with another embodiment, a station (STA) includes aprocessor, and a computer readable storage medium storing programmingfor execution by the processor, the programming including instructionsto transmit a request for access network query protocol (ANQP)information, and receive at least a portion of the requested ANQPinformation as one or more ANQP information elements (IEs) in amulticast.

In accordance with yet another embodiment, a method for access networkquery protocol (ANQP) signaling includes transmitting, by a station(STA), a request for ANQP information using a generic advertisementservice (GAS) protocol of an access point, and receiving at least aportion of the requested ANQP information as one or more ANQPinformation elements (IEs) in a beacon broadcast.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawing, in which:

FIG. 1 is a block diagram of a station (STA) and access point (AP)communication mechanisms as are known in the art;

FIG. 2 is a block diagram of a generic advertisement service (GAS)protocol;

FIG. 3 is a block diagram of adaptive network query protocol (ANQP)element information element (IE) format in accordance with variousembodiments;

FIG. 4 is a table of ANQP Info IDs in accordance with a relevantstandard;

FIGS. 5-6 are block diagrams of ANQP list IE formats in accordance withvarious embodiments; and

FIG. 7 is a block diagram illustrating a computing platform that may beused for implementing, for example, the devices and methods describedherein, in accordance with an embodiment.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of embodiments are discussed in detail below. Itshould be appreciated, however, that the present invention provides manyapplicable inventive concepts that can be embodied in a wide variety ofspecific contexts. The specific embodiments discussed are merelyillustrative of specific ways to make and use the invention, and do notlimit the scope of the invention.

Various embodiments are described in a specific context, namely accessnetwork query Protocol (ANQP) element provisioning. Various embodimentsmay also be applied, however, to other Wi-Fi transmission frameworks,such as a Wi-Fi probe query/response framework

FIG. 1 illustrates typical station (STA) and Wi-Fi network connectionoperation as is known in the art according to various standards, forexample, Hotspot 2.0, IEEE 802.11 and the like. When a STA 102 decidesto connect to a wireless network (e.g., WiFi), the UE first scans foravailable access points (AP), such as AP 104. AP 104 serves as aconnection point between STA 102 and a network 106 (e.g., a wirelesslocal area network (WLAN) in a fixed network or a wide area network(WAN)). Available APs may be connected to the same or multiple differentnetworks, wherein each AP serves as a connection point to a singlenetwork. IEEE 802.11 allows for the discovery of and informationgathering from suitable APs using several different mechanismsincluding, for example, a generic advertisement service (GAS) protocol,beacons, and probes.

A GAS protocol is a unicast query/response protocol that provides layer2 transport of information between STA 102 and AP 104 prior toassociation. GAS allows unassociated UEs to determine the availabilityof and general information regarding a particular AP through theadvertisement of certain information, such as, network 106's type (e.g.,private, public, for-fee, etc.), operator identity, location, roamingconsortium, venue information, and the like. Specifically, the GASprotocol allows STA 102 to obtain this information as access networkquery protocol (ANQP) elements.

FIG. 2 illustrates a flow diagram of a typical GAS query/responseprotocol. In step 202, a requesting STA (e.g., STA 102) transmits a GASinitial request frame to a responding STA (e.g., AP 104). The GASinitial request frame allows the requesting STA to request specifictypes of information (e.g., STA location, capabilities, operatoridentity, and the like). The types of information a STA may request isgenerally defined by a standard (e.g., IEEE 802.11 defines thisinformation in Table 8-184). In steps 204 and 206, the responding STApulls the requested information from an appropriate server (e.g., anadvertisement server). The information pulled is in the form of ANQPelements. In step 208, the responding STA then sends the requestedinformation (i.e., the ANQP elements) to the requesting STA in a GASinitial response frame. Both the GAS initial request and initialresponse frames are unicast, public action frames.

When multiple STAs (e.g., in high density scenarios such as a masstransit hubs or event stadiums) try to discover and select wirelessnetworks, multiple GAS exchanges are required. This is due to the GASprotocol being a unicast protocol. Therefore, the GAS procedure requiresmultiple request/reply protocol to relay information to multiple STAs,which, in high density scenarios, may lead to overload and delays bothin the air-interface and the backhaul of a network.

Furthermore, many of these GAS exchanges may carry the same ANQPelements (e.g., operator identity or location of an AP). Therefore,network overhead may be conserved by routing some commonly-requestedinformation carried by GAS request/response protocol to an AP'smulticast protocol. For example, an AP's beacon is a multicast protocolthat allows an AP to broadcast information. Any STA in an AP's coveragearea may simply read information off the beacon without a query/responseprocedure. Additionally, an AP may also send multicast transmissionsthrough a probe query/response protocol. A probe query/response protocoldiffers from GAS in that it allows for a responding AP to multicast aresponse to multiple requesting STAs.

In various embodiments, an AP (e.g., AP 104) may cache somecommonly-requested ANQP elements locally and multicast the requestedinformation. For instance, if an AP determines the number of requestsfor certain ANQP elements in a certain timeframe is above a threshold,the AP may cache the information in the ANQP element and multicast theinformation in a beacon broadcast. Generally, an AP multicastsinformation elements (IEs) in a particular format that is distinct fromthe format of ANQP elements sent via GAS. Therefore, various networks,STAs, and/or standards may be reconfigured to include the capability oftransmitting and/or receiving ANQP IEs in a multicast. This eliminatesthe need for the AP to continually pull ANQP elements from the serverand unicasting the ANQP elements to each requesting STA via GAS. Thetimeframe and threshold used to trigger multicasts are configurableparameters set by a network and/or in standard.

The information may be multicasted in a beacon broadcast or proberesponse/query protocol for a configurable period of time. For example,the configurable period of time may be specified in a configurationtimer corresponding to a particular ANQP IE or group of ANQP IEs set bya standard. During that time, the multicast may include an indicatorpointing to the availability of this ANQP information. When the timerexpires, the information is removed from the beacon, and the AP mayresume providing the information GAS messaging. The inclusion of aconfiguration timer ensures that the multicasted information is freshand relevant (e.g., resources aren't being expended to transmitinformation in the beacon that is no longer being requested). The AP maycontinue to monitor the number of GAS requests for the specificinformation and decide if the information should be placed back in thebeacon. For instance, the AP may monitor the number and type of ANQPinformation requested using packet inspection of the GAS messages andGAS response from the information server. Each ANQP IE may havedifferent timers and may be removed or added in the beacon at differenttimes and/or for different durations. The server may also monitor andindicate the ANQP information that should be multicasted by the AP.

In an alternative embodiment, ANQP information may be removed from amulticast (e.g., the beacon) in accordance with on other considerationsas well as a timer. For example, low traffic, low number of associatedSTAs, time of the day, operator policy, or a combination of thereof mayplay a role in an AP's decision to remove ANQP information from itsbeacon.

In various embodiments, an AP may respond in a number of ways to an STAGAS initial request. For example, the AP may determine that all theinformation requested in a GAS initial request from a STA is broadcastedin its beacon. The AP may not respond to the STA and rely on the STA toread the information from its beacon. Alternatively, the AP may signalto the STA that the information requested is in the beacon. In anotherexample, the AP may determine that only a subset of the informationrequested by a STA is in the beacon. The AP may send a GAS initialresponse containing the requested information not in the beacon andindicate the remaining subset of information is in the beacon. In yetanother alternative example, the AP may determine information requestedby a STA is in the beacon. However, the AP may still transmit theinformation requested in a GAS initial response because the APdetermines the request is urgent or the requesting STA is a legacy STA(i.e., the requesting STA is not capable of reading ANQP informationfrom a beacon). A more detailed description of a general scheme ofmulticasting ANQP elements may be found in commonly assigned U.S.Provisional Application No. 61/723,266, filed Nov. 6, 2012, entitled“Adaptive Access Network Query Protocol (ANQP) Information Provisioningin Wireless Fidelity (Wi-Fi) Beacons”, which application is herebyincorporated herein by reference.

The inclusion of an ANQP IEs in a management frame by an AP and receivedby an STA may be formatted in conformance with a standard. For example,various parameters and reference tables related to IEs may be found inthe standard, IEEE 802.11-2012, Part 11: Wireless LAN Medium AccessControl (MAC) and Physical Layer (PHY) Specifications, which isincorporated herein by reference in its entirety. FIG. 3 illustrates oneformat 300 of an ANQP IE in accordance with various embodiments. Format300 is an ANQP element IE format that an AP may use to multicast ANQPelements, for example, in a beacon broadcast. ANQP element IE format 300includes element ID field 302, length field 304, ANQP Info ID field 306,and value field 308.

Element ID field 302 is one-octet (i.e., eight bits) in length andallows a STA to identify the IE as an ANQP element IE. The value ofelement ID field 302 may be set in an IE element ID table of anapplicable standard (e.g., Table 8-54ai of IEEE 802.11). The value ofelement ID field 302 may be constant across all ANQP element IEs. Lengthfield 304 is a one-octet field that specifies the length of value field308 in octets.

ANQP info ID field 306 is a one-octet field that identifies the type ofinformation in the value field 308. That is, ANQP info ID field 306indicates to the receiving STA what genre of information value field 308contains (e.g., operator identity, AP location, or the like). The valueof ANQP info ID field 306 may be set by an applicable table in standard.For example, the value of ANQP info ID field 306 may be derived fromTable 8-184 in IEEE 802.11, portions of which are reproduced in FIG. 4for reference. Particularly, the value of ANQP info ID field 306 may beset as the value in InfoID column 400 corresponding to the appropriateANQP-element name column 402 (e.g., value 261 would indicate the ANQPelement IE contained roaming consortium information). FIG. 4 shows aportion of IEE 802.11 Table 8-184 for illustrative purposes only. Thevalues of and corresponding types of information covered by ANQP IEs mayvary and change based on the configuration of a network and relevantstandards.

Value field 308 is a field of variable length that contains thesubstantive information of the ANQP element IE. Thus, ANQP element IEformat 300 is a container for an AP to include ANQP elements in anappropriate format to be included in a beacon broadcast or proberesponse according to various embodiments.

In alternative embodiments, the ANQP information may be fragmented andtransmitted over multiple IEs in a beacon. Fragmentation may benecessary because an IE may be limited to a maximum size by an IE sizelimit standard. For example, in IEEE 802.11, an IE format has a maximumsize of 256 bits. Therefore, if the ANQP information an AP desiresmulticast exceeds this maximum size limitation, it may be fragmented andtransmitted as multiple ANQP list IEs. FIG. 5 illustrates an exampleformat 500 of ANQP list IEs. Format 500 allows for the transmission of agroup of ANQP list IEs 502, which collectively contains the informationof the requested ANQP information. ANQP list IEs 502 are sized to bewithin the maximum size limitations of an IE.

Format 500 includes an element ID field 504, a length field 506, ANQPinfo ID fields 508, ANQP fragment fields 510, ANQP length fields 512,and ANQP value fields 514. Element ID field 504 is a one-octet fieldthat identifies the IE as an ANQP list IE, and its value may be set inaccordance with a standard. For example, element ID field 504's valuemay be set by element ID table 8-54ai in IEEE 802.11. Element ID field504 may have a different value than element ID field 302 so that a STAmay distinguish between an ANQP list IE and an ANQP element IE. Lengthfield 506 is a one-octet field that specifies, in octects, the totallength of the ANQP list IE.

ANQP info ID fields 508, ANQP length fields 512, and ANQP value fields514 collectively identify the type and substantive content ofinformation contained the in each ANQP list IE 502, which collectivelyform an ANQP list IE. ANQP info ID fields 508, ANQP length fields 512,and ANQP value fields 514 may be substantially similar to correspondinglength field 304, ANQP info ID field 306, and ANQP value field 308 ofANQP element IE format 300.

ANQP fragment field 510 is a one-octet field and may be formatted inaccordance with format 600 of FIG. 6. End fragment bit 602 is one bitthat indicates if the applicable ANPQ list IE 502 is the last fragmentof the group (e.g., if end fragment is set to 0) or if another ANQP listIE follows (e.g., if end fragment is set to 1). The fragment sequencenumber bits 604 are seven bits in length and indicate the sequencenumber of the applicable ANQP list IE 502. Thus, an ANQP element may befragmented and transmitted as a group of multiple ANQP list IEs, and thecapability of ANQP transmissions in a multicast is not constrained bythe IE size limitations.

Various embodiments advantageously reduce the amount of GAS messagingrequired when particular IE(s) are requested frequently. By controllingwhich IE(s) will be broadcasted and the timing of the broadcasts, an APcan control and conserve both air-interface and backhaul traffic loads.The formatting of ANQP element IEs and ANQP list IEs enable an AP tobroadcast ANQP elements through for example, its beacon.

FIG. 7 is a block diagram of a processing system that may be used forimplementing the devices and methods disclosed herein. Specific devicesmay utilize all of the components shown, or only a subset of thecomponents, and levels of integration may vary from device to device.Furthermore, a device may contain multiple instances of a component,such as multiple processing units, processors, memories, transmitters,receivers, etc. The processing system may comprise a processing unitequipped with one or more input/output devices, such as a speaker,microphone, mouse, touchscreen, keypad, keyboard, printer, display, andthe like. The processing unit may include a central processing unit(CPU), memory, a mass storage device, a video adapter, and an I/Ointerface connected to a bus.

The bus may be one or more of any type of several bus architecturesincluding a memory bus or memory controller, a peripheral bus, videobus, or the like. The CPU may comprise any type of electronic dataprocessor. The memory may comprise any type of system memory such asstatic random access memory (SRAM), dynamic random access memory (DRAM),synchronous DRAM (SDRAM), read-only memory (ROM), a combination thereof,or the like. In an embodiment, the memory may include ROM for use atboot-up, and DRAM for program and data storage for use while executingprograms.

The mass storage device may comprise any type of storage deviceconfigured to store data, programs, and other information and to makethe data, programs, and other information accessible via the bus. Themass storage device may comprise, for example, one or more of a solidstate drive, hard disk drive, a magnetic disk drive, an optical diskdrive, or the like.

The video adapter and the I/O interface provide interfaces to coupleexternal input and output devices to the processing unit. Asillustrated, examples of input and output devices include the displaycoupled to the video adapter and the mouse/keyboard/printer coupled tothe I/O interface. Other devices may be coupled to the processing unit,and additional or fewer interface cards may be utilized. For example, aserial interface card (not shown) may be used to provide a serialinterface for a printer.

The processing unit also includes one or more network interfaces, whichmay comprise wired links, such as an Ethernet cable or the like, and/orwireless links to access nodes or different networks. The networkinterface allows the processing unit to communicate with remote unitsvia the networks. For example, the network interface may providewireless communication via one or more transmitters/transmit antennasand one or more receivers/receive antennas. In an embodiment, theprocessing unit is coupled to a local-area network or a wide-areanetwork for data processing and communications with remote devices, suchas other processing units, the Internet, remote storage facilities, orthe like.

While this invention has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications and combinations of theillustrative embodiments, as well as other embodiments of the invention,will be apparent to persons skilled in the art upon reference to thedescription. It is therefore intended that the appended claims encompassany such modifications or embodiments.

What is claimed is:
 1. A method for access network query protocol (ANQP)signaling comprising: receiving, by an access point (AP), a request forANQP information from a station (STA); determining, by the AP, a firstportion of the ANQP information was requested by a number of ANQPinformation requests within a timeframe, wherein the number of ANQPinformation requests exceeds a threshold; caching, by the AP, the firstportion of ANQP information for transmission in a multicast;multicasting, by the AP, the first portion of the ANQP information as anANQP information element (IE), wherein the ANQP IE is configured inaccordance with a format transmittable by the AP in the multicast; andunicasting, by the AP, a second portion of the ANQP information to theSTA.
 2. The method of claim 1, wherein multicasting the first portion ofthe ANQP information comprises using a beacon broadcast of the AP or aprobe query/response protocol of the AP.
 3. The method of claim 1,wherein unicasting the second portion of the ANQP information comprisesunicasting the second portion of the ANQP information in a genericadvertisement service (GAS) response.
 4. The method of claim 1, whereinmulticasting the first portion of the ANQP information comprisesmulticasting each ANQP element of the first portion of the ANQPinformation as a single ANQP element information element (IE).
 5. Themethod of claim 1, wherein multicasting the first portion of the ANQPinformation comprises multicasting each ANQP element of the firstportion of the ANQP information as a plurality ANQP list informationelements (IEs).
 6. The method of claim 1, wherein the formattransmittable by the AP in a multicast is configured in conformance witha standard.
 7. An access point (AP) comprising: a processor; and anon-transitory computer readable storage medium storing programming forexecution by the processor, the programming including instructions to:receive, by the AP, a request for adaptive network query protocol (ANQP)information from a station (STA); determine, by the AP, a first portionof the ANQP information was requested by a number of ANQP informationrequests within a timeframe, wherein the number of ANQP informationrequests exceeds a threshold; cache, by the AP, the first portion ofANQP information for transmission in a multicast; format, by the AP,first ANQP elements corresponding to the first portion of the ANQPinformation requested by the STA as one or more ANQP informationelements (IEs), wherein the ANQP IEs are configured in a multicastformat; include, by the AP, the one or more ANQP IEs in the multicast;and unicast, by the AP, second ANQP elements corresponding to a secondportion of the ANQP information requested by the STA to the STA.
 8. TheAP of claim 7, the instructions to format the first ANQP elementscomprises instructions to format at least one of the first ANQP elementsas an ANQP element IE comprising an element ID field allowing the STA toidentify the ANQP element IE as an ANQP element IE, a length fieldindicating a length of an ANQP value field, an ANQP info ID fieldindicating a type of information contained in the ANQP value field, theANQP value field, or a combination thereof.
 9. The AP of claim 7,wherein the instructions to format the first ANQP elements comprisesinstructions to format at least one of the first ANQP elements as aplurality of ANQP list IEs each comprising a ANQP fragment field,wherein the ANQP fragment field indicates whether an ANQP list IE is alast ANQP list IE in the plurality of ANQP list IEs.
 10. The AP of claim7, wherein the programming further comprises instructions to remove theANQP IEs from the multicast in accordance with an expiration of a timer,traffic load, number of associated STAs, time of day, operator policy,or a combination thereof.
 11. The AP of claim 7, wherein the programmingfurther comprises instructions pull the ANQP information requested bythe STA from a server as a plurality of ANQP elements.
 12. The AP ofclaim 11, wherein the programming further comprises instructions toreceive an indication from a server regarding which ones of theplurality of ANQP elements to include in the multicast.
 13. The AP ofclaim 7, wherein the programming includes further instructions totransmit an indicator to the STA, wherein the indicator indicates thefirst portion of the ANQP information is included in the multicast. 14.The AP of claim 7, wherein the programming includes further instructionsto format the second ANQP elements in a different format that the firstANQP elements.
 15. A station (STA) comprising: a processor; and anon-transitory computer readable storage medium storing programming forexecution by the processor, the programming including instructions to:transmit a request for adaptive network query protocol (ANQP)information; receive, from an access point, a first portion of the ANQPinformation as one or more ANQP information elements (IEs) in amulticast; receive, from the access point, a second portion of the ANQPinformation as one or more ANQP elements, wherein the one or more ANQPelements is in a different format than the ANQP IEs; and receive, fromthe access point, a subsequent multicast from which the one or more ANQPIEs were removed in accordance with an expiration of a timer, trafficload, number of associated STAs, time of day, operator policy, or acombination thereof.
 16. The STA of claim 15, wherein the instructionsto receive the second portion of ANQP information comprises receivingthe second portion of the ANQP information in a generic advertisementservice (GAS) unicast.
 17. The STA of claim 15, wherein the instructionsto receive the one or more ANQP IEs comprise instructions to receive anANQP element IE, a plurality of ANQP list IEs, or a combination thereof.18. The STA of claim 15, wherein the instructions to transmit a requestfor ANQP information includes instructions to use a genericadvertisement service (GAS) protocol of an access point.
 19. A methodfor adaptive network query protocol (ANQP) signaling comprising:transmitting, by a station (STA), a request for ANQP information;receiving, by the STA from an access point, a first portion of therequested ANQP information as one or more ANQP information elements(IEs) in a multicast; receiving, by the STA from the access point, asecond portion of the requested ANQP information as one or more ANQPelements in a unicast, wherein the one or more ANQP IEs is in adifferent format than the ANQP elements; and receiving, by the STA fromthe access point, a subsequent multicast from which the one or more ANQPIEs were removed in accordance with an expiration of a timer, trafficload, number of associated STAs, time of day, operator policy, or acombination thereof.